In recent years, from the viewpoint of global environmental protection, lamps using a low-power and long-life light emitting diode (hereinafter, referred to as an “LED” in the present specification) as a light source are becoming popular. In particular, the development of a high-intensity white LED has made the LED available for widespread use, allowing an LED lamp incorporating the LED and a driving circuit for turning on the LED to come into frequent use not only as a surface light source type lighting apparatus but also as household lighting, for which the LED has not been used conventionally because of its high cost or the like, as an alternative to an incandescent lamp, a fluorescent tube, and a bulb shape fluorescent lamp.
As such a bulb shape LED lamp to be used as an alternative to an incandescent lamp for use in a lighting apparatus for an incandescent lamp, it is proposed to arrange a heat sink plate on which the LED is mounted and a circuit board on which a driving circuit is mounted apart from each other, thereby preventing electronic components on the driving circuit board from being damaged by the heat generated when light is emitted from the LED (see Patent Document 1).